I’m struggling financially because of CSA

Been reading this site for a while and thought i would just share my dealings with the csa.
i’ll keep it as brief as i can, but basically, after my ex and i split in 2001 ,i was paying her £30 a week for our 2 kids, after i asked her to sign a book saying she had accepted this money she refused and went through the csa.

anyway i started paying regular maintenance,until about 2005 when i was out of work, i informed the csa that i was no longer working and presumed that was that. 2 years later i get a bill saying i owed nearly £3000 in arrears, they had no record of me informing them of my being out of work.
after another year i received a letter saying i was being hit with a DOE for maintenance payments and arrears.

after nearly 3 years i presumed the arrears had been paid off, how wrong i was! in fact not only had a not paid the arrears off,they had increased to over £4000!
after over a year of requesting a full breakdown i have still received nothing.
i am now struggling financially,unable to pay my bills because i moved into a flat and now once my rent is paid there is hardly nothing left.i told the csa this but they couldn’t care less.
i have involved my mp and written, phoned many times but just get the same old fobbing off.